CHARACTERIZATION OF VACUUM RESIDS,HYDROCRACKED PRODUCTS AND ASPHALTENES BY PYROLYSIS-GAS CHROMATOGRAPHY (FID-FPD)

ABSTRACT

This paper describes an exploratory study on the characterization of oil heavy-end fractions through pyrolysis coupled with gas chromatography. A pulse heating pyrolyzer with a platinum-strip sample holder, directly coupled with a capillary column gas chromatograph and equipped with a universal detector (FID) and a sulfur-selective detector (FPD), was used for that purpose.

An analysis of vacuum residua, asphaltenes and resins from different crudes was made, as well as analogous fractions from the hydrocracking products of these vacuum residua. Hydrocarbon qualitative profiles (pyrograms) were very much alike for all fractions studied. However, some differences were observed in pyrogram intensity. In general, fractions from untreated samples showed more intense signals than those from the hydrotreated ones. Besides, each of the fractions from vacuum residua generated more intense pyrograms than the combination thereof (entire residue). It was possible to correlate the process-ability of a vacuum residue during hydrocracking and its hydrocarbon yield in analytical pyrolysis.     

REACTIVITY OF SULPHUR SPECIES IN BITUMEN PITCH AND RESIDUA DURING FLUID COKING AND HYDROCRACKING

X-ray photoelectron spectroscopy (XPS) was used to determine sulphur species and their distribution in fractions of fluid coking residue (CK) and hydro-cracking residue (HC) derived from an Athabasca bitumen pitch (ABP). The major sulphur species were sulphides/mercaptans and thiophenes in each case. No sulphoxides and sulphones were detected in any non-oxidised samples. Each residua was separated into between 9 and 15 front-cut samples and a single end-cut fraction by supercritical fluid extraction and fractionation (SFEF). This approach has been used to produce different molecular weight fractions, depending on the severity of separation conditions. In the fractions from the parent Athabasca bitumen pitch about 65-80 wt% of the total sulphur occurs as thiophenes with the remainder being sulphide species. The reactivity of the sulphur species in the parent pitch was determined under mild conditions using a standard technique for selective oxidation. In this procedure sulphides are preferentially oxidized to sulphoxides while thiophenic sulphur remains unchanged; under the same reaction conditions the degree of sulphide conversion generally declined with increasing molecular weight of the fractions. Commercial catalytic hydrocracking completely removed sulphides from the front-cut fractions of the parent pitch. However, the composition of the end-cut fraction from the residua produced by this process was virtually the same as that for the comparable fraction from fluid coking. This observation demonstrates that hydrocracking has little effect on intractable heavy ends. Also, hydrocracking removed only a relatively small proportion of thiophenic sulphur. On the other hand, while commercial fluid coking removed most of the sulphides from the parent pitch the residue was enriched with thiophene compared to the parent feed. This observation demonstrates the partitioning effect occurring during coking reactions.     

Kinetic Study on the Hydrocracking Reaction of Vacuum Residue Using a Lumping Model

Based on the experimental hydrocracking of vacuum residue, a kinetic study using a lumping model was carried out to gain insight into the characteristics of catalytic reactions. The lumped species were the saturates, aromatics, resins, and asphaltenes (SARA) constituents in the residue (798 K⁺) fraction and gas, naphtha, kerosene, gas oil, vacuum gas oil, and coke in the products. The pyrite reaction favoring hydrocracking to lighter products was more temperature-dependent than that using a mixture of pyrite and active carbon. The kinetic study showed that the addition of active carbon to pyrite limited the transformation of resins to asphaltenes.     

Colloidal Structures of Daqing and Gudao Vacuum Residua and Their Formation

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Kinetic Study on the Hydrocracking Reaction of Vacuum Residue Using a Lumping Model

Abstract

Based on the experimental hydrocracking of vacuum residue, a kinetic study using a lumping model was carried out to gain insight into the characteristics of catalytic reactions. The lumped species were the saturates, aromatics, resins, and asphaltenes (SARA) constituents in the residue (798 K⁺) fraction and gas, naphtha, kerosene, gas oil, vacuum gas oil, and coke in the products. The pyrite reaction favoring hydrocracking to lighter products was more temperature-dependent than that using a mixture of pyrite and active carbon. The kinetic study showed that the addition of active carbon to pyrite limited the transformation of resins to asphaltenes.     

大孔Ni-Mo/Al2O3催化剂上重馏分油加氢脱硫生产低硫船用燃料油

根据浆态床渣油加氢裂化与重馏分油加氢脱硫相结合的工艺生产低硫船用调合燃料油技术路线,采用两种不同大孔结构的Ni-Mo/Al₂O₃加氢脱硫催化剂,以Merey减压渣油浆态床加氢裂化重馏分油产物为原料开展催化剂的加氢脱硫反应性能研究。采用XRD、XRF、N2吸附-脱附、SEM、EDS、Py-FTIR、TG-DTG-DrDTA等方法对两种新鲜催化剂(HDS-A和HDS-B)和硫化后催化剂进行对比分析。实验结果表明,HDS-B因具有更为丰富的比表面积和大孔孔道结构,而表现出优异的重馏分油加氢脱硫反应活性;反应温度为320℃时,HDS-B的脱硫率和脱硫重馏分油硫含量分别达到70.34%和0.36%(w),满足残渣型船用燃料油硫含量低于0.5%(w)的最新标准要求;继续提升反应温度,脱硫重馏分油的硫含量进一步降低。     

减压渣油物性数学模型的建立与仿真

对大庆、大港、孤岛、胜利、华北、沙特6种减压渣油的宽、窄馏分实验数据进行回归分析，得到几组减压渣油物性关联式。在此基础上选定减压渣油的特征性质，借助BP模型神经计算的非线性拟合能力，在行为水平上进行建模与仿真。     

四川油砂油主要馏分性质及加工方案

对四川油砂油进行了模拟蒸馏分析,获得了馏程分布。对油砂油的直馏柴油(200～350℃)、减压馏分油(350～500℃)和减压渣油(大于500℃)进行了物理性质测定。结果表明,以沸腾床LC-Fining法加氢裂化与延迟焦化组合工艺为四川油砂油的加工方案,可以获得收率(达到76.62%)较高、质量较好的轻质燃料油,同时柴汽比(质量比)为4.10。     

原油减压渣油馏分的油-水界面性质Ⅴ.表面活性剂对减渣馏分油-水界面粘度的影响

采用剪切界面粘度仪考察了表面活性剂Tween40和Span80的油 水界面粘度及其对大庆、伊朗轻质和伊朗重质减压渣油馏分的油 水界面粘度的影响。结果表明,随着油相中Tween40、Span80和油相中芳烃质量分数的增加,油 水界面粘度均增大。并且,当油相中Tween40、Span80的临界胶束(CMC)质量分数在其质量分数变化范围内时,油 水界面粘度有大幅度的增加。Tween40铺展吸附于油 水界面,其油 水界面粘度较大。Span80竖立吸附于油 水界面,其油 水界面粘度较小。Tween40取代减渣馏分铺展吸附于油 水界面,其油 水界面粘度较低,相互间的差别也较小,随着油相中Tween40质量分数的增大,油 水界面粘度降低。Span80楔入减渣馏分油 水界面吸附层,共同构成油 水界面结构。对线性结构多的减渣馏分,随着油相中Span80质量分数的增大,油 水界面粘度逐渐增大。对芳香稠环结构多的减渣馏分,随着油相中Span80质量分数的增大,油 水界面粘度逐渐减小。     

原油减压渣油馏分的油-水界面性质Ⅺ.伊朗轻质减压渣油和大庆减压渣油乳状液的粒度特征

采用动态光散射法研究了伊朗轻质减压渣油和大庆减压渣油模拟乳状液的粒度特征。研究表明，伊朗轻质减压渣油和大庆减压渣油模拟乳状液的初始粒径较小，粒度分布较窄；随着时间的延长，其粒径逐渐增大，粒度分布变宽；随着馏分增重或体相质量浓度的增加，模拟乳状液的初始粒径增大。随着油相中芳烃含量增加，伊朗轻质减压渣油和大庆减压渣油中重馏分模拟乳状液的初始粒径增大，而大庆减压渣油轻馏分模拟乳状液的初始粒径减小。随着水相中碱或盐的加入，伊朗轻质减压渣油和大庆减压渣油模拟乳状液的初始粒径均增大。     

Deposition of Coke in Pyrolysis of Vacuum Gasoil after Hydrocracking

Research data on pyrolysis of the residue from light hydrocracking of heavy feedstock on a laboratory setup are reported. The more severe the hydrocracking process, the less the coke deposited on the walls of the reactor tubes during pyrolysis. This is probably due to a decrease in the content of components prone to coking in the residue: primarily bi and polycyclic aromatic hydrocarbons.     

优化蒸汽裂解原料及增产柴油技术措施的探讨

介绍燕化公司为优化乙烯裂解原料的构成和增产柴油将要采取的几项技术及措施,采用减压渣油催化裂化中压加氢裂化组合技术,将１Ｍｔ／ａ中压加氢改质装置改造为１．３Ｍｔ／ａ中压加氢裂化装置,新建天然气制氢装置;新建１Ｍｔ／ａ柴油有制装置,适当加工部分轻质原油。     

渣油加氢脱硫装置进料过滤器的改进

齐鲁石油化工公司胜利炼油厂在蜡油加氢裂化装置和渣油加氢脱硫装置试验使用了绕丝管和金属丝网2种不同形式的原料过滤器 ,结果表明 :在过滤减压蜡油时 2种过滤器均可 ,且金属丝网形式滤芯反冲洗周期更长。而在过滤减压渣油时两种过滤器均无法正常运行 ,绕丝管形式的滤芯配上金属丝网外壳则具有较好的反冲洗性能 ,更适合在渣油加氢装置使用     

Properties, Compositions and Structure Characteristics of Kazakhstan and Russian Vacuum Residua

Kazakhstan vacuum residue (KAZVR) and Russia vacuum residue (RUSVR) were respectively cut into a number of narrow cuts and non-extractable end-cut by supercritical fluid extraction and fractionation (SFEF). The properties distribution and SARA compositions of the fractions were analyzed, structure parameters and structure configurations were determined by means of the modified BL method based on 13C-NMR and 1H-NMR data. The results show uneven enriching of contaminants in heavier fractions and much complex structure for end-cuts and removing end-cuts from residua will greatly favor further upgrading. The results would help detailed understanding of KAZVR and RUSVR and their processing adaptability.     

减压渣油掺炼煤焦油相容性及加氢处理研究

采用沸腾床渣油加氢处理工艺对掺炼一定比例煤焦油的劣质渣油进行加氢处理研究,考察其产品分布情况;并采用斑点试验、不稳定性参数试验对混合原料的相容性及加氢处理后体系的稳定性进行考察。试验结果表明：劣质渣油与煤焦油按7：3比例混合进行加氢处理,小于500 ℃馏分油收率增加24.33百分点,焦炭产率降低;相容性方面,混合原料的相容性要差于纯减渣原料,但经加氢处理后,混合原料稳定性得到大幅改善,而减渣原料稳定性降低。     

渣油悬浮床加氢工艺Ni液溶胶催化剂

以水溶性Ni盐溶液为前体,制备了硫化态Ni催化剂的液溶胶体系。对Ni胶体催化剂和水溶性催化剂在原料油中的分散状况进行了观察分析,并对加氢裂化反应后两种催化剂的存在状态进行了SEM、XPS和激光粒度表征。结果表明,硫化态Ni液溶胶催化剂比水溶性Ni催化剂在原料油中分散颗粒度小,比表面积大,分散均匀。Ni胶体催化剂和水溶性Ni催化剂存在下渣油加氢裂化反应后,催化剂中Ni元素主要以Ni²⁺的形式存在,S主要以S²⁺和S⁶⁺两种形式存在,胶体催化剂在反应后无明显团聚现象。两种催化剂存在下渣油加氢裂化反应生焦数据表明, Ni胶体催化剂比水溶性Ni催化剂具有更高的抑制生焦活性。     

渣油悬浮床加氢裂化与固定床加氢脱硫工艺的比较

比较了渣油固定床加氢脱硫工艺和渣油悬浮床加氢裂化工艺的流程设计特点、建设投资、原料性质、反应条件及产品分布和性质。渣油固定床加氢脱硫 催化裂化组合工艺 ,可以将渣油彻底转化 ,有效合理地解决了含硫渣油的出路问题 ,而且国内有成熟的技术和催化剂 ,但柴油质量差 ,汽油达不到环保的要求 ,而且建设投资较大 ,催化剂费用较高。渣油悬浮床加氢裂化 在线加氢精制组合工艺 ,可以生产出作为催化重整原料的石脑油、高十六烷值的优质柴油和作为催化裂化原料的加氢蜡油 ,残渣仅有 5 %左右 ,而且建设投资较小 ,催化剂费用较低 ,但国内尚无此工艺的应用经验。在加工渣油时选用固定床加氢脱硫工艺还是悬浮床加氢裂化工艺 ,应根据所用原料的性质和加工的目的而定。     

悬浮床加氢裂化集总动力学模型的研究

在不同反应温度、氢初压条件下,通过高压反应釜对克拉玛依常压渣油（KLAR）进行加氢裂化实验,以此模拟悬浮床加氢裂化过程,并根据实验数据及实际工艺中对各种轻油产品收率预测的需求建立了悬浮床加氢裂化六集总（气体、汽油、柴油、蜡油、减压渣油、焦）动力学模型,用matlab软件进行编程,采用最小二乘法对动力学参数进行估算,并进行误差分析。结果表明,建立的六集总动力学模型能很好的对各集总产品收率进行预测,计算结果与实验值基本吻合,大部分误差在5%以内。     

委内瑞拉减压渣油的热解特性及其动力学研究

采用热重-质谱(TG-MS)联用对委内瑞拉减压渣油在不同升温速率下进行热解实验,研究其热解反应特性,并采用3种等转化率法和分布活化能模型(DEAM)求取减压渣油热解反应的动力学参数。实验结果表明,委内瑞拉减压渣油的热解主要反应温度区间为179～490℃,总质量损失率为77.54%,质量损失峰值在446℃达到最大,最大质量损失速率为317.38μg/min。Flynn-Wall-Ozawa(FWO)法比其他2种等转化率法能更好地描述减压渣油的热解过程,由其计算得到的热解活化能为56.77～178.91 kJ/mol。进一步采用DEAM模型将减压渣油分为4个假定组分,对升温速率为10℃/min条件下的热重分析(TG-DTG)数据进行分峰拟合,求得饱和分、芳香分、胶质和沥青质四组分动力学参数,并据此获得减压渣油总活化能分布曲线。结果表明,委内瑞拉减压渣油活化能主要集中在100～250 kJ/mol范围内,通过加权求和获得平均活化能为190.11 kJ/mol。     

减压蜡油加氢裂化催化剂组合动力学模型

以高压加氢裂化六集总动力学模型为基础,建立预测催化剂组合体系产品分布的数学模型。按固定馏程间隔将原料油和加氢裂化生成油划分为减压蜡油 加氢裂化尾油（>360℃）、柴油馏分（290～360℃）、喷气燃料馏分（175～290℃）、重石脑油馏分（65～175℃）、轻石脑油馏分（<65℃）和炼厂气（C4-）6个集总。分别以2种不同类型加氢裂化催化剂的实验数据为基础,采用Matlab 2011b数值计算软件和非线性最小二乘法对动力学模型参数进行了优化回归。以优化回归后的动力学模型参数为初值,调整部分模型参数,建立了预测催化剂组合体系产品分布的数学模型。用该模型计算得到的加氢裂化产品分布与实验值之间的一致性较好,其偏差均小于2%。